Characterization of activated carbon prepared by phosphoric acid activation of olive stones

AbstractThe effects of activating agent concentration on the pore structure and surface chemistry of activated carbons derived from olive stone with chemical activation method using phosphoric acid as the activating agent were studied. Mass changes associated with the impregnation, carbonization and washing processes were measured. With H3PO4 dilute solutions (60, 70, and 80 wt% H3PO4), the loading of substance on CS increases with concentration. The concentration of the H3PO4 solution seems to control the processes of impregnation, carbonization and washing in the preparation of AC from olive stones by H3PO4 chemical activation. ACs have been characterized from the results obtained by N2 adsorption at 77K. Moreover, the fractal dimension (D) has been calculated in order to determine the AC surface roughness degree. Optimal textural properties of ACs have been obtained by chemical activation with H3PO4 80wt.%. The BET surface areas and total pore volumes of the carbons produced at H3PO4 80wt.% are 1218m2/g and 0.6cm3/g, respectively

Favorable Changes in Fasting Glucose in a 6-month Self-Monitored Lifestyle Modification Programme Inversely Affects Spexin Levels in Females with Prediabetes

Spexin (SPX) is a novel peptide thought to have a role in various metabolic regulations. Given its presumed body-weight regulatory functions, we aimed to determine whether lifestyle intervention programs on weight loss and fasting glucose (FG) improvement among people with impaired glucose regulation also alter levels of circulating SPX. A total of 160 Saudi adult males and females with prediabetes were randomly selected from a larger cohort (N = 294) who underwent a 6-month lifestyle modification program to improve their glycemic status. Participants were split into two groups based on differences in glucose levels post-intervention, with the first 50% (improved group) having the most significant reduction in FG. SPX was measured at baseline and after 6 months. Changes in SPX was significant only in the improved group [baseline: median (Q1\u2013Q3) of 164 pg/ml (136\u2013227) vs follow-up: 176 pg/ml (146\u2013285); p < 0.01]. When stratified by sex, the significant increase was observed only in females [159 pg/ml (127\u2013252) vs 182.5 (152,369.1); p < 0.01]. Furthermore, SPX levels showed a significant inverse association with FG (\u3b2 = 120.22, p = 0.003) even after adjustment with age and BMI, again only in females. Circulating SPX levels increase over time in people with prediabetes, particularly women who responded favorably in a 6-month lifestyle intervention program. Whether an unknown mechanism regulating the sexual disparity seen in SPX levels post-intervention exists should be further investigated using a larger sample size

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Removal of Trihalomethanes from Aqueous Solution through Adsorption and Photodegradation

Trihalomethanes (THMs) are carcinogenic by-products of disinfection that are present in drinking water. In the present research, adsorption and photodegradation, either individually or in tandem, were employed for the removal of the principal THMs found in water supply systems. The effects of pH, contact time, adsorbents and adsorbate concentration on the adsorption system were investigated. The Langmuir and Freundlich adsorption isotherm models were used to analyze the resulting adsorption data. Photodegradation of THMs was carried out in the presence and absence of activated carbon. The integration of adsorption and photodegradation systems as a hybrid treatment process resulted in a synergetic enhancement of the THM removal efficiency. The kinetics of THM removal were found to follow the pseudo-second-order model rather than the Langmuir–Hinshelwood pseudo-first-order model

Effect of acute downhill running on bone markers in responders and non-responders

Summary: This study showed that procollagen type 1 amino-terminal pro-peptide and N-MID osteocalcin significantly increased after exercise independent of the form of muscle contraction. Thus, these preliminary results will be useful for future studies that will consider bone turnover characteristics of responders and non-responders to acute and chronic aerobic exercise. Introduction: The aim of the current study was to compare the effects of acute flat running (FR) and downhill running (DHR) on bone turnover markers in men. Methods: Fourteen healthy young active men performed three exercise tests in a ounterbalanced order, including rest condition, FR, and DHR, at 60% maximal aerobic capacity on a treadmill with 0 and − 12% inclines. Blood samples were taken in the preexercise, immediately post-exercise, and 24-h post-exercise periods, and bone markers included total procollagen type 1 aminoterminal pro-peptide (total PINP) and N-MID osteocalcin. Results: Total P1NP significantly increased after exercise independent of the form of muscle contraction (p > 0.05). N-MID osteocalcin increased after DHR by 17% compared to after pre-exercise, but the difference did not reach significance (p =0.07; partial eta square, 0.21). Biomarker responses to exercise were dependent on the exercise form and independent of hormone type in half of the participants who were classified as responders. Physiological parameters and changes in muscle voluntary contraction did not explain the differences between responders and non-responders. Conclusion: The effect of acute DHR on bone turnover is determined by biomarker type and participant characteristics. Future studies should discriminate between the characteristics of responders and those of non-responders

Removal of Cobalt-60 and Caesium-134 Ions from Contaminated Solutions by Sorption Using Activated Carbon

Date pits (DP) and sawdust (SD) were used as precursors for activated carbons which were prepared by steam pyrolysis of DP and chemical activation of SD, respectively. Surface characterization of both activated carbons was undertaken using the BET method. Adsorption of the radionuclides onto the activated carbon was studied as a function of shaking time, adsorbent mass and pH employing the batch technique. Such adsorption was strongly dependent on the pH of the aqueous medium in contact with the adsorbent, with the removal efficiency attaining a maximum at pH 6. The process was very fast initially, with maximum adsorption being attained within 180 min of initial contact. The adsorption rate could be best fitted by the pseudo-second-order kinetic model. The equilibrium data were analyzed using the Freundlich, Langmuir, Langmuir–Freundlich, Dubinin– Radushkevich, Temkin and Frumkin isotherms. The Langmuir–Freundlich and Frumkin equations were found to best represent the equilibrium data for both radionuclides. The isotherm model constants were determined and used to characterize the distribution of 60 Co and 134 Cs ions onto the adsorbent surfaces and to provide an insight into the affinity of the adsorbents towards these ions